JP7294215B2 - Conveyor and machine tools - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveying device and a machine tool having an arm.

2. Description of the Related Art In recent years, machine tools equipped with transfer devices for transferring objects such as tools and works have become widespread.
A machine tool described in Patent Document 1 includes a robot arm having a gripping portion for an object such as a tool or a workpiece at the tip of the arm. A robot arm moves inside and outside the processing area by a movement mechanism to convey the object.

JP 2016-55370 A

On the other hand, for some reason, the position of the object may deviate from the normal position. In this case, the gripping portion cannot reliably grip the object, and problems such as the object dropping during transportation may occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a conveying apparatus and a machine tool that can reliably grip and convey an object even if the position of the object is shifted.

A conveying device according to the present invention is a conveying device comprising an arm including two movable members that rotate about a predetermined axis, and further comprising a connecting member interposed between the two movable members and connecting the two movable members. , the connecting member has a first member and a second member arranged side by side in the direction of the axis, and the first member and the second member are arranged in the direction of the axis or in a direction crossing the axis It is connected so that relative displacement is possible.

In the present invention, since the first member and the second member can be relatively displaced in the direction of the axis or in the direction intersecting the axis, the gripping posture corresponding to the positional change of the object due to contact with the object. can take Therefore, even if the position of the object deviates from the normal position, the object can be reliably gripped.

In the conveying device according to the present invention, the first member and the second member are ring-shaped, and the first member is loosely fitted to the second member.

In the present invention, since the first member is loosely fitted to the second member, the first member and the second member can be relatively displaced in the direction of the axis or in the direction crossing the axis.

In the conveying device according to the present invention, the connecting member has a biasing member that biases the first member so as to reduce the amount of displacement.

In the present invention, the urging member urges the first member to bring them into close contact with each other, suppresses displacement of the first member or the second member, and reduces the amount of displacement.

The conveying device according to the present invention comprises a seal interposed between the first member and the second member.

In the present invention, the seal intervenes between the first member and the second member, and can prevent dust and the like from entering between the first member and the second member.

In the conveying device according to the present invention, one of the two movable members is a hand that grips the target object.

In the present invention, one movable member is the hand, and the connecting member is interposed between the hand and the other movable member. Therefore, the hand can be displaced to take a gripping posture corresponding to the positional change of the object.

A machine tool according to the present invention includes any one of the transport devices described above, and processes a work transported by the transport device.

In the present invention, the machine tool processes the work conveyed by the conveying device.

ADVANTAGE OF THE INVENTION According to this invention, even when the position of an object shifts, an object can be reliably hold|gripped and conveyed.

It is a perspective view showing a machine tool concerning an embodiment. It is a side view of an arm device. FIG. 3 is a vertical cross-sectional view of a portion surrounded by a dashed line in FIG. 2; It is a perspective view which shows the connection member of an arm apparatus. 4 is an exploded view of a connecting member; FIG. It is sectional drawing of a 1st member and a 2nd member. It is a sectional view of a connection member.

A conveying device and a machine tool according to embodiments of the present invention will be described below with reference to the drawings. In the following description, top and bottom, left and right, and front and rear are used.

FIG. 1 is a perspective view showing a machine tool 100 according to an embodiment. The machine tool 100 has a cover 101 surrounding the machining area. An opening 42 is provided in the right side wall of the cover 101 . A door 43 sliding in the front-rear direction opens and closes the opening 42 . A work exchanging device 1 (conveying device) is provided on the right side of the opening 42 .

A work exchanging device 1 exchanges a work used for machining. The workpiece exchanging device 1 includes an arm device 10 and a base portion 12 that holds the arm device 10 . The base portion 12 has a housing shape extending in the front-rear direction, and has an opening on its upper surface. The arm device 10 rises upward from the opening of the base portion 12 .

The machine tool 100 includes a control box 50 that controls the drive of the workpiece changer 1 (arm device 10). The control box 50 includes a CPU, ROM, RAM, and the like. The CPU loads the control program stored in the ROM into the RAM and executes it, thereby controlling the driving of the machine tool 100 and the workpiece exchanging device 1 .

FIG. 2 is a side view of the arm device 10. FIG.
The arm device 10 includes a first arm portion 31 (movable member), a second arm portion 32 (movable member), a holding portion 33 and a base portion 34 .

Base 34 is fixed to base 12 . The holding portion 33 is arranged on the base portion 34 and holds one end portion 311 of the first arm portion 31 . The first arm portion 31 is rotatable around an axis in the front-rear direction. The other end portion 312 of the first arm portion 31 holds one end portion 321 of the second arm portion 32 . The second arm portion 32 is rotatable around an axis in the front-rear direction.

A hand 60 for gripping an object such as a work is attached to the other end portion 322 of the second arm portion 32 . FIG. 3 is a vertical cross-sectional view of a portion surrounded by a dashed line in FIG.
A gripper motor 323 for rotating the hand 60 (movable member) is provided inside the second arm 32 . The gripper motor 323 is coupled to a speed reducer 324 including bevel gears.

A hand 60 is arranged behind the reduction gear 324 . The reduction gear 324 is connected to the gripper motor 323 via a bevel gear. The hand 60 is connected to the output side of the reduction gear 324 via a connecting member 20 which will be described later.
That is, the second arm portion 32 holds the hand 60 via the speed reducer 324 and the connecting member 20 , and the rotation of the gripper motor 323 is transmitted to the hand 60 via the speed reducer 324 and the connecting member 20 .

The hand 60 has a rotating portion 62 and a gripping portion 61 . The rotating portion 62 has a recessed portion 621 , which will be described later, and is engaged with a portion of the connecting member 20 . The gripping portion 61 is attached to the rotating portion 62 . The gripping portion 61 rotates as the rotation portion 62 rotates due to the rotation of the gripping portion motor 323 .

Between the second arm portion 32 and the hand 60, a connecting member 20 that connects the reduction gear 324 (the second arm portion 32) and the hand 60 is interposed. The connecting member 20 has an annular shape and includes a first member 21 and a second member 22 . The first member 21 engages the rotating portion 62 and the second member 22 engages an output disk 326, which will be described later.

As described above, inside the second arm portion 32, the grip portion motor 323 is provided with the output shaft directed downward. A reduction gear 324 is provided below the gripper motor 323 . The speed reducer 324 has a bevel gear on the input side, and an output disk 326 is provided on the output side of the speed reducer 324 .

An input side (bevel gear) of a reduction gear 324 is connected to the output shaft of the motor 323 for gripping portion. The output disc 326 has an annular shape with a through hole in the center and is fixed to the output side of the reduction gear 324 . The connecting member 20 is connected to the output side of the reduction gear 324 via the output disc 326 .

A cylindrical tubular member 329 is fitted in the center of the reduction gear 324 and the output disk 326 . The tubular member 329 has an enlarged diameter at one end and opens to the front side of the second arm portion 32 . A pipe (not shown) for supplying air to the cylinder for the grasping portion 61 of the hand 60 passes through the cylindrical member 329 .

The output disk 326 rotates around the rotation axis J. The output disc 326 has a ring-shaped protruding part in the center that protrudes toward the hand 60 along the rotation axis J, and the protruding part engages with the second member 22 of the connecting member 20. there is

The rotating part 62 of the hand 60 has a circular recess 621 in the center, and the recess 621 has a through hole 63 passing through the rotating part 62 along the rotation axis J in the center of the bottom. The recessed portion 621 has a dimension that enables engagement with the first member 21 of the connecting member 20 .

4 is a perspective view showing the connecting member 20 of the arm device 10, and FIG. 5 is an exploded view of the connecting member 20. As shown in FIG.
The first member 21 and the second member 22 are connected by four bolts 27 and assembled. FIG. 4 shows the assembled state. A ring-shaped inner seal 23 , an outer seal 24 and four springs 25 are interposed between the first member 21 and the second member 22 . The inner seal 23 and the outer seal 24 are for example lip seals and are deformable. The spring 25 is cylindrical and deformable.
The bolt 27 is, for example, a reamer bolt, and has a head at one end, a male threaded end at the other end, and a cylindrical body portion excluding the head and the male threaded end.

6 are cross-sectional views of the first member 21 and the second member 22 , FIG. 6A showing the first member 21 and FIG. 6B showing the second member 22 . FIG. 7 is a cross-sectional view of the connecting member 20. As shown in FIG.

The first member 21 has a central hole 212 that penetrates the first member 21 in the thickness direction. The central hole 212 gradually increases in diameter from one surface 218 on the hand 60 side toward the other surface 219 on the second member 22 side.

That is, a fitting portion 214 for fitting a part of the second member 22 is formed on the other surface 219 by enlarging one side of the central hole 212 . A seal groove portion 213 for accommodating the inner seal 23 is formed between the one surface 218 and the fitting portion 214 . The central hole 212 is expanded in diameter to form a seal groove portion 213 , and the seal groove portion 213 is expanded in diameter to form a fitting portion 214 . The seal groove portion 213 and the fitting portion 214 are formed coaxially.

The inner seal 23 is fitted in the seal groove portion 213 . The outer diameter of the inner seal 23 is equal to the inner diameter of the seal groove portion 213 , and the inner diameter of the inner seal 23 is equal to the inner diameter of the other side of the central hole 212 .

The first member 21 has four fixing holes 217 and four fixed holes 220 at regular intervals around the central hole 212 . The fixing holes 217 and the fixed holes 220 are arranged alternately and at equal intervals on the same circumference. The fixed hole 220 is a through hole through which a bolt (not shown) is passed to fix the first member 21 to the rotating portion 62 of the hand 60 .

The fixing hole 217 is a through hole through which the bolt 27 is passed. A counterbore 211 is formed on one side of the one surface 218 side, and a counterbore 215 is formed on the other side of the other surface 219 side. A counterbore 211 accommodates the head of the bolt 27 and a counterbore 215 accommodates the body of the bolt 27 .

The inner diameter of the counterbore 211 is greater than the outer diameter of the head of the bolt 27, and the depth of the counterbore 211 is greater than the height of the head of the bolt 27, so that the counterbore 211 can accommodate the head. A gap exists between the head of the bolt 27 and the inner wall of the counterbore 211 . Four disk-shaped packings 26 cover the counterbore 211 (see FIG. 5).

A portion of the fixing hole 217 excluding the counterbores 211 and 215 (hereinafter referred to as an intermediate portion of the fixing hole 217) has an inner diameter larger than the outer diameter of the body portion of the bolt 27. The dimension in the thickness direction is shorter than the length of the body. A gap exists between the body of the bolt 27 and the inner wall of the intermediate portion of the fixing hole 217 .

The counterbore 215 has an inner diameter larger than the inner diameter of the intermediate portion of the fixing hole 217 and accommodates the spring 25 . The bolt 27 passes through the spring 25 when the first member 21 and the second member 22 are assembled. The outer diameter of the spring 25 is substantially equal to the inner diameter of the counterbore 215 , and the inner diameter of the spring 25 is larger than the outer diameter of the body of the bolt 27 . The depth of counterbore 215 is smaller than the natural length of spring 25 .

A seal groove 216 for fitting the outer seal 24 is formed in the outer peripheral edge of the first member 21 on the side of the other surface 219 . The outer diameter of the outer seal 24 is approximately equal to the outer diameter of the first member 21 .

The second member 22 includes a disk portion 224 having a diameter larger than that of the first member 21 and an inner fitting portion 221 that fits inside the fitting portion 214 of the first member 21 . The inner fitting portion 221 has an annular shape and protrudes from the central portion of one surface 227 of the disk portion 224 . The inner fitting portion 221 and the disk portion 224 are positioned on the same axis.

The second member 22 has a through hole 222 penetrating in the thickness direction in the central portion. One side of the through hole 222 is open to the end surface of the inner fitting portion 221 , and the other side is enlarged to form an enlarged diameter portion 226 . The through hole 222 has the same diameter as the central hole 212 of the first member 21 . The enlarged diameter portion 226 opens to the other surface 228 opposite to the one surface 227 . The enlarged diameter portion 226 has an inner diameter larger than that of the through hole 222 . The protruding portion of the output disc 326 fits inside the enlarged diameter portion 226 .

Four female screw holes 225 are formed at regular intervals around the inner fitting portion 221 on one surface 227 of the disk portion 224 . The female screw hole 225 is a hole for screwing the male screw end of the bolt 27 and is formed at a position corresponding to the fixing hole 217 of the first member 21 .

The outer diameter of the inner fitting portion 221 of the second member 22 is smaller than the inner diameter of the fitting portion 214 of the first member 21 . The inner fitting portion 221 fits into the fitting portion 214 with a gap. The central hole 212 of the first member 21 and the through hole 222 of the second member 22 communicate with each other. The central hole 212 of the first member 21 communicates with the through hole 63 of the rotating portion 62 of the hand 60 . Through the central hole 212 of the first member 21 and the through hole 222 of the second member 22, a pipe (not shown) for supplying air to the cylinder for the gripping portion 61 passes.

In the second member 22, four fixing holes 229 are formed at regular intervals in the edge of the disk portion 224. As shown in FIG. One side of the fixing hole 229 on the side of the one surface 227 is enlarged to form a counterbore 223 . Fixing holes 229 pass bolts (not shown) that fix the second member 22 to the output disk 326, and the counterbore 223 accommodates the heads of the bolts. The inner diameter of fixing hole 229 is smaller than the inner diameter of counterbore 223 .

As shown in FIG. 7, the first member 21 can be connected to the second member 22 by inserting the bolt 27 into the fixing hole 217 and screwing it into the female screw hole 225 of the second member 22 . A male threaded end portion of the bolt 27 passes through the fixing hole 217 from the one surface 218 side of the first member 21 and is screwed into the female threaded hole 225 of the second member 22 .

As described above, the outer diameter of the inner fitting portion 221 of the second member 22 is smaller than the inner diameter of the fitting portion 214 of the first member 21 , and the inner fitting portion 221 is loosely fitted inside the fitting portion 214 . Therefore, a gap G4 is formed between the inner wall of the fitting portion 214 and the outer peripheral surface of the inner fitting portion 221 .

The depth of the counterbore 211 of the first member 21 is greater than the height of the head of the bolt 27 . Each packing 26 covers the head of each bolt 27 and covers the counterbore 211 . The packing 26 has the same diameter as the inner diameter of the counterbore 211 and is made of rubber, for example. One side of the packing 26 is flush with the one side 218 and the other side is in contact with the head of the bolt 27 .

The second member 22 is attached to the output disc 326 by inserting a bolt (not shown) into the fixing hole 229 and screwing it into a female screw hole (not shown) formed in the output disc 326 . can be fixed. The first member 21 can be fixed to the hand 60 by passing a bolt (not shown) through a through hole formed in the rotating portion 62 of the hand 60 and screwing it into the fixing hole 220 of the first member 21 .

A spring 25 is inserted through the bolt 27 , and the spring 25 is interposed between the inner wall of the counterbore 215 and the body of the bolt 27 . A gap exists between the body of the bolt 27 and the spring 25 . The inner diameter of the counterbore 211 is larger than the outer diameter of the head of the bolt 27 , and a gap exists between the head of the bolt 27 and the inner wall of the counterbore 211 . Further, there is a gap between the body of the bolt 27 and the intermediate part of the fixing hole 217 , and there is also a gap between the body of the bolt 27 and the spring 25 .
In the following, the distance between the head of the bolt 27 and the inner wall of the counterbore 211, the distance between the body of the bolt 27 and the inner wall of the intermediate portion of the fixing hole 217, the body of the bolt 27 and the spring 25 , that is, the space around the bolt 27 is collectively referred to as the space G2.

As described above, the natural length of the spring 25 is longer than the depth of the counterbore 215 in the thickness direction of the first member 21 (the direction of the rotation axis J). When the first member 21 and the second member 22 are connected, one end surface of the spring 25 contacts the bottom of the counterbore 215 and the other end surface of the spring 25 faces the other surface 219 of the first member 21 . It abuts on one surface 227 of member 22 .

Therefore, the spring 25 biases the first member 21 in a direction away from the second member 22, and the bottom of the counterbore 211 and the head of the bolt 27 are in close contact (see the broken line portion in FIG. 7), and the first member A gap G1 exists between the other surface 219 of the second member 21 and the one surface 227 of the second member 22 . The spring 25 is deformable, and the first member 21 can move toward or away from the second member 22 or the second member 22 toward or away from the first member 21 along the rotation axis J within a predetermined range.

As described above, the outer seal 24 is interposed between the first member 21 and the second member 22, and the outer seal 24 allows chips to flow between the first member 21 and the second member 22 through the gap G1. prevent entry.

Further, since a gap G1 exists between the other surface 219 of the first member 21 and the one surface 227 of the second member 22, a gap G3 is also formed between the end surface of the inner fitting portion 221 and the bottom of the fitting portion 214. I have The interval G3 is approximately equal to the interval G1.
The inner seal 23 arranged in the seal groove portion 213 is in close contact with the end surface of the inner fitting portion 221 to prevent chips from entering between the first member 21 and the second member 22 through the gap G3.

In the arm device 10, the inner fitting portion 221 of the second member 22 is loosely fitted into the fitting portion 214 of the first member 21, and the gaps G1, G3, G4 are provided between the first member 21 and the second member 22. exists, and a gap G2 exists between the circumference of the bolt 27 and the first member 21 . The first member 21 is movable in the direction along the rotation axis J by the gaps G1 and G3, and is movable in the direction perpendicular to the rotation axis J by the gaps G2 and G4. That is, when the position of the first member 21 shown in FIG. 7 is the original position, the first member 21 is displaced within a predetermined range in a direction along the rotation axis J and a direction intersecting the rotation axis J. Is possible. When the first member 21 moves in the direction along the rotation axis J, the packing 26 is deformed and does not hinder the movement of the first member 21 .

That is, the second member 22 is fixed to the base portion 34 via the first arm portion 31 and the second arm portion 32 , and the first member 21 is fixed to the hand 60 . Therefore, the hand 60 can be freely offset in a direction along the rotation axis J and a direction intersecting the rotation axis J within a predetermined range.

With the above configuration, when the hand 60 (grasping portion 61) grips an object such as a work, the object can be reliably gripped even if the position of the object slightly deviates from the normal position (calculated position). be able to. The gripping part 61 can be freely displaced in a direction along the rotation axis J and in a direction intersecting the rotation axis J by contact with the object, and can take a gripping posture corresponding to the positional change of the object. . Therefore, the object can be reliably gripped.

Further, as described above, since the bottom of the counterbore 211 and the head of the bolt 27 are in close contact with each other due to the biasing force of the spring 25, friction is generated between the bottom of the counterbore 211 and the head of the bolt 27 (Fig. 7 dashed line). Therefore, the frictional force can prevent the first member 21 from being displaced in the direction orthogonal to the rotation axis J, thereby reducing the amount of displacement. Therefore, it is possible to prevent the occurrence of so-called backlash.

Although the case where the spring 25 is interposed between the bolt 27 and the first member 21 (counterbore 215) has been described above, the spring 25 is not essential and may be omitted. Even in this case, the first member 21 can be freely displaced in the direction along the rotation axis J and in the direction intersecting the rotation axis J within a predetermined range.

In the above, the case where the connecting member 20 is provided between the second arm portion 32 and the hand 60 has been described as an example. Alternatively, the connecting member 20 may be provided between the holding portion 33 and the first arm portion 31 .

Reference Signs List 1 work exchange device 10 arm device 20 connecting member 21 first member 22 second member 23 inner seal 24 outer seal 25 spring 31 first arm portion 32 second arm portion 60 hand 100 machine tool

Claims (6)

In a conveying device comprising an arm including two movable members rotating around a predetermined axis,
A connecting member interposed between the two movable members and connecting the two movable members,
The connecting member has a first member and a second member arranged side by side in the direction of the axis,
The first member is attached to one movable member of the two movable members, the second member is attached to the other movable member of the two movable members,
The conveying device in which the first member and the second member are screwed together so as to be relatively displaceable in the direction of the axis or in the direction intersecting the axis. The first member and the second member are ring-shaped,
2. The conveying apparatus of claim 1, wherein said first member is loosely fitted to said second member. 3. The conveying device according to claim 1, wherein the connecting member has a biasing member that biases the first member so as to reduce the amount of displacement. 4. A conveying device according to any one of claims 1 to 3, comprising a seal interposed between the first member and the second member. 5. The conveying apparatus according to any one of claims 1 to 4, wherein one of the two movable members is a hand that grips an object. A conveying device according to any one of claims 1 to 5,
A machine tool for processing a work conveyed by the conveying device.

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